Venous ThrombosisPortal VeinThrombosisVeinsThrombophlebitisFemoral VeinHypertension, PortalIliac VeinHypertensionPhlebographyUpper Extremity Deep Vein ThrombosisSaphenous VeinVaricose VeinsPopliteal VeinPulmonary EmbolismPortal SystemMesenteric VeinsAnticoagulantsHypertension, PulmonaryJugular VeinsSplenic VeinRenal VeinsSubclavian VeinFibrin Fibrinogen Degradation ProductsVena Cava, InferiorHeparin, Low-Molecular-WeightPulmonary VeinsUltrasonography, Doppler, DuplexLegHepatic VeinsSinus Thrombosis, IntracranialIntracranial ThrombosisVenous ThromboembolismCoronary ThrombosisPortal PressureCerebral VeinsThrombophiliaTreatment OutcomeVenous InsufficiencyAxillary VeinRisk FactorsHeparinVena Cava FiltersHypertension, RenalPostphlebitic SyndromePlethysmography, ImpedanceStockings, CompressionIntermittent Pneumatic Compression DevicesUmbilical VeinsBlood PressureTime FactorsThromboembolismProspective StudiesWarfarinBudd-Chiari SyndromeFactor VThrombectomyRetrospective StudiesPostthrombotic SyndromeBandagesFollow-Up StudiesFibrinolytic AgentsPortasystemic Shunt, SurgicalPostoperative ComplicationsProtein S DeficiencyLower ExtremityCarotid Artery ThrombosisPregnancy Complications, CardiovascularEsophageal and Gastric VaricesHypertension, RenovascularAntihypertensive AgentsHemorrhageUltrasonography, DopplerTomography, X-Ray ComputedLiver CirculationUltrasonography, Doppler, ColorRecurrenceThrombolytic TherapyActivated Protein C ResistanceHypertension, MalignantCatheterization, PeripheralVaricose UlcerIncidenceMesenteric Vascular OcclusionProthrombinEnoxaparinRisk AssessmentCatheterization, Central VenousRetinal Vein OcclusionLiver CirrhosisVascular PatencyLigationAngiographyBrachiocephalic VeinsVenous PressureFibrinogenAzygos VeinSplenorenal Shunt, SurgicalVenous ValvesVascular Surgical Procedures